U.S. patent number 4,764,683 [Application Number 07/080,920] was granted by the patent office on 1988-08-16 for wind powered electric generator.
This patent grant is currently assigned to Lloyd A. Smith. Invention is credited to Donald E. Coombes.
United States Patent |
4,764,683 |
Coombes |
August 16, 1988 |
Wind powered electric generator
Abstract
An improved wind powered generator includes a streamlined
housing rotatably connected with a fixed base and a pair of helical
rotors rotatably connected with the housing for driving a pair of
electric generators when the rotors are rotated by the wind. The
housing includes forward and rear nacelles which define vertical
side openings in the housing in which the rotors are arranged, with
the helical vanes thereof partially protruding from the housing.
The nacelles serve to direct the wind stream against the rotor
vanes with minimal disturbance, whereby the helical rotors capture
the maximum amount of kinetic energy from the wind for conversion
to electricity.
Inventors: |
Coombes; Donald E. (Baker,
OR) |
Assignee: |
Smith; Lloyd A. (Baker,
OR)
|
Family
ID: |
22160506 |
Appl.
No.: |
07/080,920 |
Filed: |
August 3, 1987 |
Current U.S.
Class: |
290/55; 290/44;
415/60; 415/907; 416/DIG.4; 416/121; 416/197A |
Current CPC
Class: |
F03D
9/25 (20160501); F03D 3/02 (20130101); F03D
3/0454 (20130101); F05B 2240/2212 (20130101); Y02E
10/74 (20130101); Y10S 416/04 (20130101); F03D
80/70 (20160501); Y10S 415/907 (20130101) |
Current International
Class: |
F03D
3/00 (20060101); F03D 3/04 (20060101); F03D
007/00 (); F03D 009/00 () |
Field of
Search: |
;290/54,43,55,44
;416/197A,DIG.4 ;415/2R,3R,2A,60,213R |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
2300235 |
|
Oct 1976 |
|
FR |
|
157071 |
|
Sep 1982 |
|
JP |
|
Primary Examiner: Shoop, Jr.; William M.
Assistant Examiner: Logan; Sharon D.
Attorney, Agent or Firm: Laubscher & Laubscher
Claims
What is claimed is:
1. Apparatus for driving an electric generator in response to fluid
currents such as wind, water, and the like, comprising
(a) a fixed base;
(b) a vertical housing rotatably connected with said base, said
housing including tapered front and rear portions with said front
portion facing the fluid current and terminating in a vertical edge
having a pointed horizontal cross-sectional configuration, aid side
portions containing vertical openings extending the length of said
housing and defined between said front and rear portions;
(c) vertical rotor means arranged within said housing openings and
rotatably connected with said housing, said rotor means including
at least one helical vane protruding partially exteriorly of said
housing, whereby fluid current passing said housing strikes the
vanes to rotate said rotor means; and
(d) means for coupling said rotor means with at least one
generator, whereby rotary movement of said rotor means drives the
generator to produce electricity.
2. Apparatus as defined in claim 1, wherein said rotor means
comprises a pair of rotors each being arranged in a housing opening
on opposite sides thereof, respectively, said rotors each
containing an axial rotor shaft and a tubular body concentrically
arranged relative to said shaft, said helical vanes extending
outwardly from the outer surface of said tube.
3. Apparatus for driving an electric generator in response to fluid
currents such as wind, water, and the like, comprising
(a) a fixed based;
(b) a vertical housing rotatably connected with said base, said
housing including
(1) streamlined front and rear nacelles with said front nacelle
facing the fluid current; and
(2) side portions containing vertical openings extending the length
of said housing and defined between said front and rear
nacelles;
(c) a pair of rotors each arranged within a housing opening on
opposite sides thereof, respectively, and rotatably connected with
said housing, each of said rotors including an axial rotor shaft, a
tubular body concentrically arranged relative to said shaft, and at
least one helical vane extending outwardly from the outer surface
of said tube and protruding partially exteriorly of said housing,
whereby fluid current passing said housing strikes said vanes to
rotate said rotors; and
(d) means for coupling said rotors with at least one generator,
whereby rotary movement of said rotor means drives the generator to
produce electricity. arranged in a housing opening on opposite
sides thereof, respectively, said rotors each containing an axial
rotor shaft and a tubular body concentrically arranged relative to
said shaft, said helical vanes extending outwardly from the outer
surface of said tube.
4. Apparatus as defined in claim 3, wherein said rear housing
nacelle contains at least one opening in the rearwardmost edge
thereof to vent any fluid pressure generated within said housing as
a result of rotation of said rotors.
5. Apparatus as defined in claim 3, wherein said forward housing
nacelle is adjustable in a direction transverse to the current
direction, thereby to control the degree of protrusion of said
rotor vanes into the current stream.
6. Apparatus as defined in claim 5, wherein said generator coupling
means comprises a chain and sprocket drive assembly including a
plurality of sprockets connected with said rotors and the
generator, respectively, and at least one chain connected between
said sprockets.
7. Apparatus as defined in claim 6, wherein said housing includes a
rigid framework comprising upper and lower crosspieces with which
said nacelles and rotors are connected and vertical interior struts
connected between said upper and lower crosspieces.
8. Apparatus as defined in claim 5, wherein said base includes a
rigid spider assembly for supporting the top of said housing.
9. Apparatus as defined in claim 8, and further comprising bearing
means rotatably connecting said housing with said base and spider
assembly, respectively, whereby said housing is free to rotate in
accordance with the changes in the direction of the fluid current
in order to maintain said housing front portion facing the fluid
current.
10. Apparatus as defined in claim 9, and further comprising a brake
and snubbing assembly connected between said base and said housing
to control the rotational movement of said housing relative to said
base.
Description
BACKGROUND OF THE INVENTION
The present invention relates to an improved assembly for driving a
generator to generate electricity using the energy in a fluid
current, particularly wind. The kinetic energy of the wind is
harnessed by a unique double helical rotor assembly which is driven
by the wind to in turn drive one or more electric generators.
BRIEF DESCRIPTION OF THE PRIOR ART
The kinetic energy of blowing wind has long been converted to
mechanical energy, such as by a windmill, to operate a pump, grind
grain and the like.
A major drawback of the windmill type devices is that in order to
harness enough energy to drive an electric generator, the windmill
has to be excessively large and located in an area of high constant
wind. The size of the conventional blades results in a constant
chopping sound which is distracting and becomes unpleasant and
uncomfortable after a short period of time of operation.
Accordingly, attempts have been made to improve upon conventional
windmills by providing wind energy harnessing devices having
various blade configurations as evidenced by the U.S. Pat. Nos.
4,156,580 Pohl, 4,265,086 Bahrenburg, 4,293,274 Gilman, and
4,369,629 Lockwood. The Pohl patent for example discloses a
vertical axis wind turbine including a pair of prismatic rotors
mounted behind a wind deflecting shield of a tower structure. The
Gilman patent also discloses a vertical axis wind turbine having a
single rotor including helical vanes.
While the prior devices normally operate satisfactorily, they each
possess certain drawbacks which limit their efficiency with regard
to energy conversion. This is generally due to the inability to
properly direct the wind against the rotors to maximize rotor
rotation for energy conversion. Gilman provides adjustable vanes
for capturing the wind in accordance with the amount of wind
present. Pohl provides a forward deflector which, owing to its
non-aerodynamic configuration, actually diffuses and thus
diminishes the wind stream or current. Moreover, the prism
configuration of the rotors of the Pohl device produces a beating
or chopping sound during operation, much like the blades of a
helicopter, which is environmentally unpleasant.
The present invention was developed in order to overcome these and
other drawbacks of the prior wind generators by providing a
streamlined device of maximum efficiency which quietly converts
wind or other fluid current energy into electricity.
SUMMARY OF THE INVENTION
Accordingly, it is a primary object of the present invention to
provide a wind or other fluid current driven electric generator
including a base, a vertically arranged housing rotatably connected
with the base, a pair of helical rotors rotatably connected with
the housing, and an assembly for coupling the rotors with an
electric generator, whereby rotation of the rotors by the wind
drives the generator to produce electricity. More particularly, the
housing comprises forward and rear nacelles, with the forward
nacelle facing the wind. At each side of the housing is a vertical
opening defined between the forward and rear nacelles. Within each
opening is arranged a rotor having one or more helical vanes, with
the rotors being rotatably connected with the housing and
protruding at least partially exteriorly thereof, whereby the vanes
intercept the wind stream delivered to the openings by the forward
nacelle. The rear nacelle contains at least one opening in the
rearwardmost edge thereof to vent the fluid pressure created within
the housing as a result of rotation of the rotors.
According to a more specific object of the invention, each rotor
comprises a vertically arranged axial shaft with a tubular body
concentrically arranged relative to the shaft. The tubular body
serves to direct and compress the airflow onto the helical vanes of
the rotors to increase efficiency.
It is a further object of the invention to provide an adjustment
mechanism operable to transversely adjust the walls of the forward
nacelle to control the degree of protrusion of the rotor vanes into
the wind stream, thereby controlling the maximum output of the
rotors for a given wind speed.
According to yet another object of the invention, the housing
includes a rigid framework with which the forward and rear nacelles
and the rotors are connected. The framework is connected with the
base via bearings, whereby the housing is free to rotate into the
wind much like a weathervane so that the maximum volume of wind is
intercepted by the rotors. A brake and snubbing assembly is
connected between the base and the housing relative to the base to
prevent the housing from yawing or to lock the housing in a given
orientation.
BRIEF DESCRIPTION OF THE FIGURES
Other objects and advantages of the subject invention will become
apparent from a study of the following specification when viewed in
the light of the accompanying drawing, in which:
FIG. 1 is a side plan view of the wind powered generator according
to the invention;
FIG. 2 is a sectional view of the housing of the wind powered
generator taken along line 2--2 of FIG. 1;
FIG. 3 is a side plan view of the housing framework;
FIG. 4 is a sectional view of the framework taken along line 4--4
of FIG. 3.
FIG. 5 is a partial rear plan view of the front nacelle adjustment
mechanism; and
FIG. 6 is a partial detailed view of the housing brake and snubber
assembly and of the mechanism for coupling the rotors with a pair
of electric generators.
DETAILED DESCRIPTION
As shown in FIG. 1, the wind power generator 2 of the present
invention includes a fixed base 4 and a vertical housing 6
rotatably connected therewith. More particularly, the housing is
tapered and includes a lower vertical shaft 8 connected with the
base 4 via a bearing and unit lock-down brake assembly 10. In order
to stabilize the top of the housing, a fixed stabilizer assembly 12
is provided. The stabilizer assembly includes a vertical shaft 14
connected with the top of the housing 6 via a bearing 16 and a
spider assembly including longitudinal and lateral cross pieces 18,
20 connected with the shaft 14. The ends of the cross pieces 18, 20
have guy wires 22 connected therewith for anchoring the stabilizer
assembly 12 with the ground or other support. Struts 24 are
connected between the ends of the cross pieces and the shaft 14 to
increase stability.
Referring now to FIGS. 3 and 4, the housing 6 comprises a rigid
framework connected with the bearings. The framework essentially
comprises upper and lower crosspieces 26, 28 and a pair of vertical
struts 30 connected therebetween. As shown in FIGS. 1 and 3, the
vertical axis of rotation 32 of the housing relative to the base
and spider is parallel to but forward of the geometric vertical
axis of the housing. As will be developed below, this arrangement
assists the housing to rotate to face or find the wind direction in
the same manner as a weathervane.
Referring now to FIGS. 1 and 2, the housing 6 also includes a
forward nacelle 34 and a rear nacelle 36 connected with the
framework, with the forward nacelle being that which faces the wind
as shown by the arrows. The nacelles each have an aerodynamic or
streamlined outer surface configuration to provide undisturbed
airflow across the surface of the housing. At the sides of the
housing are vertical openings defined between the front and rear
nacelles. Arranged within each opening is a rotor 38 having a
vertical axial rotor shaft 40 connected with the lateral portions
26a, 28a of the upper and lower framework crosspieces 26, 28. More
particularly, the rotor shafts are connected with the housing
framework by bearing and brake assemblies 39, whereby the rotors
rotate relative to the housing. The rotors 38 also include a
cylindrical tube 42 connected with the shaft 40 by horizontal
spokes 44. Connected with the outer surface of the tubes, and
preferably formed integrally therewith are a plurality of helical
vanes 46. In the embodiment shown in FIG. 2, one rotor 38a has two
vanes while the other rotor 38b has four vanes.
The rotors are mounted on the housing framework such that the rotor
vanes 46 partially protrude exteriorly of the housing as shown in
FIG. 2 to intercept the wind delivered off of the rear edge of the
forward nacelle. The wind thus rotates the rotors in opposite
directions, with the speed of rotation being a function of the
speed of the wind and of the degree of protrusion of the vanes
exteriorly of the housing.
The degree of protrusion of the rotor vanes is controlled through
an adjustment of the transverse orientation of the walls 34a of the
forward nacelle. More particulaly, the walls 34a are connected at
their forward edges by a vertical hinge 48 as shown in FIG. 2 to
define an angle .alpha. therebetween. An adjustment mechanism,
shown in detail in FIG. 5, is connected with the forward nacelle
walls to vary the angle .alpha. therebetween. A vertical post 48 is
connected between the longitudinal members 26b, 28b of the housing
frame upper and lower cross pieces. A movable collar 50 is mounted
on the post 48 and struts 52 are pivotally linked between the
collar and the inner surface of the forward nacelle walls 34a. A
nacelle control device 54 controls the vertical movement of the
collar 50 relative to the post 48. As the collar moves downwardly
from the position shown in FIG. 5, the struts are extended
outwardly to increase the angle .alpha. between the walls 34a
thereby spreading the walls transversely outwardly and concealing a
greater portion of the rotor vanes. When the collar is moved
upwardly, the walls are drawn inwardly, whereby the rotor vanes
protrude a greater degree exteriorly of the housing.
Referring once again to FIG. 2, it is seen that the rear nacelle
contains at the rearwardmost edge thereof at least one opening 56.
This opening serves to vent or siphon off high pressure air trapped
with the housing as a result of rotation of the rotors. The vent
opening thus allows the rotors to rotate more freely and also
contributes to a smooth air flow at the rear of the housing.
FIG. 6 illustrates in detail how the rotary energy from the rotors
is coupled to electric generators. The shaft 44 of each rotor
includes a sprocket 58 which rotates with the rotor shaft. A pair
of chains 60 is connected with and driven by the rotor sprockets,
and a pair of generators 62, 64 is connected with the housing frame
lower cross piece 28. Each generator includes an input drive shaft
having sprockets 66 connected therewith. The chains 60 from the
rotor sprockets are connected with the generator sprockets to drive
the input shafts thereof. The orientation of the chain and sprocket
drive coupling mechanism is also shown schematically in FIG. 2.
Owing to the chain drive path, the oppositely rotating rotors both
drive the generator input shafts in the same direction.
Also shown in FIG. 6 is a brake and snubbing assembly for the
housing. The housing shaft 8 includes a sprocket 68 which is
connected via a chain 70 with the sprocket 72 of a hydraulic
snubber 74 connected with the base 4. The snubber can be controlled
to limit the degree of rotation of the housing shaft 8 and thus the
housing relative to the base to prevent the housing from yawing in
a variable wind. Moreover, the snubber can be locked in a given
position to brake or arrest all rotary movement of the housing
relative to the base. The snubber may be controlled either manually
or automatically to provide manual or automatic braking, such as in
storm conditions or when repair is required.
While the invention has been described for use primarily as a
device for converting wind energy into electricity, it may be
adapted for use in any moving fluid current such as water. In this
environment, it may be beneficial to mount the device horizontally
facing the direction of fluid flow since it is desirable to locate
the device in an area where the flow is uniform and preferably at
its highest value.
An important benefit realized from using rotors with helical vanes
is that the lifting action is created within the nacelles upon
rotation of the rotors. This creates an updraft out of the top of
the nacelles which reduces air pressure on the inside blades.
Reduced drag on the vanes increases rotor speed which is an
important factor in light winds. The lifting action also reduces
the load on the base rotor shaft bearings which reduces maintenance
costs.
While in accordance with the provisions of the patent statute the
preferred forms and embodiments of the invention have been
illustrated and described, it will be apparent to those skilled in
the art that various changes and modifications may be made without
deviating from the inventive concepts set forth above.
* * * * *